Sealing material for gasometers



Patented Aug. 30, 1927.

UNITED STATES PATENT OFFICE.

ROBERT HEZGER, F STUTTGABT, GERMANY, ASSIGNOIB '10 PAUL LEOHLER, OF

' I STUTTGABT, GERMANY, A FIRE.

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No Drawing. Application filed Ill'ovember 21, 1985, Serial IllTo. 70,710, and in Germany December 8, 1924.

' My invention refers to a new roduct for use in sealing the gap between a ry gasometer casing and the disc movable therein, such gasometers' being frequently used to 6 replace 'the old type of water-sealed gasometers. It isan object of my invention to provide means whereby the movable disc is packed in a gas-tight manner without its movability within the casing being impaired 10 and without danger of the substance used for packing or sealing being affected by the gas and by other causes.

In gasometers of the type aforesaid as hitherto in use the gap between the movable disc and the outer casing is sealed as a rule by means of high temperature coal tar and the products of distillation obtained therefrom. It is generally inexpensive to use these substances inasmuch. as this tar is obtained as a by-product inthe' manufacture 86 cally connected and operated in an automatlc'm'anner are frequently affected by the thickening of the tar inasmuch as theoverloading arisin in consequence of such thickening causes are fuses to burnout. How- 40 ever, if the attendant fails to notice this, the pumps will not work for a longer time and inconsequence thereof the sealing will suffer so that comparatively great losses of gas may result.. Moreover the most valuable parts of the tar are lost, the as being at the same time carburetted, and t ese parts must be replaced, whereby the costs of operatin a gasometer are undul increased. A thic ened tar further has a igher freezing point as com ared with the thmly fluid tar initially use and in consequence of this raising of the freezing point the operation its lighter and even some of its 'tained after a short rest. certained that all draw-backs are .easily obof a gasometer can be disturbed in winter unless suflicient heating is provided at. all points'where there is danger of freezing. t has'also beennoticed' that the water precipitated from the gas, suchas water-gas, w

en cooling down, combines with the tar to form an emulsionand can be separated again from the tar only with great difliculty and only in very large gasometers, such emulsions being; so stable that for instance, even after an o eration of four months the percentage 0 water in the tar has been found to. be not less than-twenty .percent. Obviously a high content of water will tend'to further raisethe freezing point of the.tar, but the most dangerous. consequ'ence is the formation of ice on the inner walls of the g'asometer which renders a ti ht sealing im ossible and forms a furt er source of anger; It is also evident that emulsions of this character will give rise to corrosion of the gasometer walls.

As is 'well known to any expert, a tar in order to-be fit for use as a sealing means for gasometers, must not suffer any perceptible. change of boiling point curve and freezing point, if air is caused to pass throligh it for'6 hours at a temperature of 60 On being vigorously shaken with water in a separating funnel a. clear separation of the water from the tar must .be ob- I have now asviated if the high temperature coal tar and the products resulting therefrom are replaced by a solution of mineral bitumen ina mineral oil, brown coal tar oil or an oil. obtained by distillation of low temperature coal tar. I prefer using as a solvent mineral oils having a bo ling point curve starting at a high -temperature,-for instance 300? (l, a low freezing point, preferably not above 20 0., and the highest possible flash point. The. bitumen to be dissolved in an oil of this kind should be such as to dissolve therein without producing any slimy residue.

In producing a solution which is well adapted for sealing purposes as hereinbefore described, I may for instance dissolve twenty parts mineral oil pitch ineighty parts mineral oil having a specific gravity of 0,915, a flash point of 153- (3. and a freesing point below -22 U, this oil, when subjected to fractional distillation resulting in the following fractions:

Asolution of the kind mentioned above, when. used for sealing the disc in a gasometer, will not suffer any variation of its low freezing point; it will not thicken and ill stand the test mentioned above (passage oi air at 60- 0.). With water the solution will not form an emulsion, the

water being separated out after a short rest,

so as to be easily removed from time to time by hand or by mechanical means. In consequence thereof there does not exist any danger of corrosion, the new product on the contrary forming an excellent means for preventing" rusting of the walls. The term mineral oil used in the appended claims is intended to include ordinary mineral oil, brown coal tar oil and low temperature coal tar oil, all containing a large percentage of parailines.

I wish it to be understood that I do not desire to be limited to the exact substances, proportions and temperatures above deatinas scribed, for obvious modifications will occur to a person skilled in the art.

l c aim 1. As a new composition of matter for the sealing of gasometer discs, a solution of mineral bitumen in a mineral oil, said oil starting to boil at about 300 6., having a freezing point not above -20 and a flashpoint not below 150 C.

2. As a new composition of matter for the sealing of gasometer discs, a solution of mineral Oll pitch in a mineral oil, said oil starting boiling at about 300- C. having freezing point not above -2() C. and a dash point not below 150- C.

3 As a new composition of matter for the sealing of gasometer discs, a solution of 20 parts mineral oil pitch in 80 parts min eral oil having a specific gravity of about 0.915, a flash point of 153 C. and a freezing point below 22 C.

A sealing liquid for dry gasometers of the movable disc type comprising a'mineral bituminous material and an oil vehi ole therefor, said oil vehicle being an oil consisting largely of aliphatic hydrocarbone, containing no substantial fractions boiling below 300 (3., said oil having a dash point not substantially below 153" (1., having a freezing point substantially below that of water, and being substantially unailected by illuminating gases.

lln testimony whereof I aflix my signature.

ROBERT MEZGER. 

